s390/pci: fix handling of PEC 306

In contrast to other hotplug events PEC 0x306 isn't about a single
but multiple devices. Also there's no information on what happened
to these devices. We correctly handled hotplug that way but failed
to handle hot-unplug. This patch addresses that and implements
hot-unplug of multiple devices via PEC 306.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/pci.h

@@ -161,9 +161,9 @@ int zpci_create_device(struct zpci_dev *);
 void zpci_remove_device(struct zpci_dev *zdev);
 int zpci_enable_device(struct zpci_dev *);
 int zpci_disable_device(struct zpci_dev *);
-void zpci_stop_device(struct zpci_dev *);
 int zpci_register_ioat(struct zpci_dev *, u8, u64, u64, u64);
 int zpci_unregister_ioat(struct zpci_dev *, u8);
+void zpci_remove_reserved_devices(void);
 
 /* CLP */
 int clp_scan_pci_devices(void);

arch/s390/pci/pci.c

@@ -86,6 +86,25 @@ struct zpci_dev *get_zdev_by_fid(u32 fid)
 	return zdev;
 }
 
+void zpci_remove_reserved_devices(void)
+{
+	struct zpci_dev *tmp, *zdev;
+	enum zpci_state state;
+	LIST_HEAD(remove);
+
+	spin_lock(&zpci_list_lock);
+	list_for_each_entry_safe(zdev, tmp, &zpci_list, entry) {
+		if (zdev->state == ZPCI_FN_STATE_STANDBY &&
+		    !clp_get_state(zdev->fid, &state) &&
+		    state == ZPCI_FN_STATE_RESERVED)
+			list_move_tail(&zdev->entry, &remove);
+	}
+	spin_unlock(&zpci_list_lock);
+
+	list_for_each_entry_safe(zdev, tmp, &remove, entry)
+		zpci_remove_device(zdev);
+}
+
 static struct zpci_dev *get_zdev_by_bus(struct pci_bus *bus)
 {
 	return (bus && bus->sysdata) ? (struct zpci_dev *) bus->sysdata : NULL;
@@ -845,16 +864,6 @@ int zpci_create_device(struct zpci_dev *zdev)
 	return rc;
 }
 
-void zpci_stop_device(struct zpci_dev *zdev)
-{
-	zpci_dma_exit_device(zdev);
-	/*
-	 * Note: SCLP disables fh via set-pci-fn so don't
-	 * do that here.
-	 */
-}
-EXPORT_SYMBOL_GPL(zpci_stop_device);
-
 void zpci_remove_device(struct zpci_dev *zdev)
 {
 	if (!zdev->bus)

arch/s390/pci/pci_clp.c

@@ -334,14 +334,6 @@ static int clp_list_pci(struct clp_req_rsp_list_pci *rrb, void *data,
 }
 
 static void __clp_add(struct clp_fh_list_entry *entry, void *data)
-{
-	if (!entry->vendor_id)
-		return;
-
-	clp_add_pci_device(entry->fid, entry->fh, entry->config_state);
-}
-
-static void __clp_rescan(struct clp_fh_list_entry *entry, void *data)
 {
 	struct zpci_dev *zdev;
 
@@ -349,19 +341,8 @@ static void __clp_rescan(struct clp_fh_list_entry *entry, void *data)
 		return;
 
 	zdev = get_zdev_by_fid(entry->fid);
-	if (!zdev) {
+	if (!zdev)
 		clp_add_pci_device(entry->fid, entry->fh, entry->config_state);
-		return;
-	}
-
-	if (!entry->config_state) {
-		/*
-		 * The handle is already disabled, that means no iota/irq freeing via
-		 * the firmware interfaces anymore. Need to free resources manually
-		 * (DMA memory, debug, sysfs)...
-		 */
-		zpci_stop_device(zdev);
-	}
 }
 
 static void __clp_update(struct clp_fh_list_entry *entry, void *data)
@@ -398,11 +379,13 @@ int clp_rescan_pci_devices(void)
 	struct clp_req_rsp_list_pci *rrb;
 	int rc;
 
+	zpci_remove_reserved_devices();
+
 	rrb = clp_alloc_block(GFP_KERNEL);
 	if (!rrb)
 		return -ENOMEM;
 
-	rc = clp_list_pci(rrb, NULL, __clp_rescan);
+	rc = clp_list_pci(rrb, NULL, __clp_add);
 
 	clp_free_block(rrb);
 	return rc;